The present invention relates to a sizing means and method for sizing a flexible tubular food casing during the stuffing thereof. In particular, the present invention relates to an expandable sizing means together with a method for using the sizing means.
Automatic and semiautomatic systems for stuffing food casings with a variety of food products as well known in the meat packing industry.
For production of encased products on a fully automatic basis, shirred casing is used. Shirred casing is a relatively long continuous length of casing of up to 200 feet or more which is shirred to a much shorter length. Other stuffing operations may use shorter, cut lengths of casing which are not shirred.
It is also common to use a casing sizing means in connection with the stuffing of relatively large casings which, for example, may range between 50 and 200 millimeters in diameter. These casings have a relatively thick wall, often reinforced with a fibrous web. The stuffing of these larger casings is often facilitated by diametrically stretching the casing just prior to stuffing.
This diametrical stretching can be accomplished by longitudinally passing the casing over stationary sizing means and allowing the sizing means to stretch the casing to a predetermined diameter. The friction between the longitudinally moving casing and stationary sizing means also creates an amount of drag or hold-back force on the casing. While this drag or hold-back force, in part, contributes to the final diameter of the stuffed casing product, it also determines the extent to which the casing is filled. In general, the greater the hold-back force or drag on the casing, the more fully and tightly packed the casing will be with food product.
While diametrical sizing and holdback is desired to provide a uniform, fully stuffed encased product, there are times during the stuffing operation when the casing should be relatively free of the drag or hold-back force created by the sizing means. For example, during automatic stuffing operations using the larger sizes of casing, it is periodically necessary to provide an amount of casing slack, as when the stuffing apparatus is operated to gather and close the casing around the ends of the stuffed product. Reducing the drag or hold-back force on the casing in order to produce an amount of casing slack facilitates the gathering and closing operation.
Sizing means as used in the stuffing of larger sizes of casing having either a fixed diameter as shown, for example, in U.S. Pat. Nos. 4,007,761 and 4,335,488, or an adjustable diameter as shown in U.S. Pat. Nos. 3,457,588 and 4,202,075. The latter type, in turn, can comprise elements which are integral components of the stuffing apparatus (U.S. Pat. No. 3,457,588) or they can be attachable to the stuffing apparatus (U.S. Pat. No. 4,202,075).
The present invention is an expandable sizing means of the type which is readily attachable to the stuffing apparatus. Moreover, the sizing means of the present invention can be expanded to a fixed casing stretching size by the act of attaching the sizing means to the stuffing apparatus. This facilitates use of the sizing means in that it can be easily implanted into a casing in a collapsed or unexpanded state and then expanded to a casing stretching size when the casing and sizing means are mounted to the stuffing apparatus.
Thus, the sizing means of the present invention lends itself to sale either as a component of a casing article (casing plus sizing means) or as a separate item. For example when sold as a component of a casing article, preferably together with a shirred casing length, the sizing means is simply implanted into an unshirred portion of the casing and the casing is closed over the sizing means. In its collapsed state, the diameter of the sizing means is preferably smaller than the diameter of the unshirred, unstretched casing, so that the sizing means can be easily inserted into the unshirred casing portion.
In use, the sizing means is automatically expanded to a fixed casing stretching size as the casing article is mounted to the stuffing apparatus. Thereafter, casing slack, if needed, can be provided by operation of a conventional slacker mechanism as shown for example, in U.S. Pat. No. 4,044,426 or by other means known in the art.
The sizing means can be used either with shirred or cut lengths of casing. When used with shirring casing, the sizing means, in a collapsed or unexpanded condition, is inserted into the casing by the user and then is mounted to the stuffing apparatus. In the alternative, the casing is loaded onto the stuffing machine, then the sizing means is put into position, and then the casing is pulled over the sizing means.